The invention concerns a timber element.
The invention also concerns a procedure for manufacturing a timber element.
Round timbers and dressed timber made from one log are known in prior art. These normal, conventional timbers are frequently subject to cracking as the dry out, in such a way that the splits and cracks become visible on the side faces, that is, in the walls of the timber building. The detriment from such cracks is, primarily, aesthetic deficiency: a cracked wall surface is no nice view. A further drawback resulting from the cracks is impaired insulating capacity of the wall and, further, ready access of water from the exterior surface, through the cracks into the wood, where damage is likely to ensue.
The state of art knows a timber element which is composed of at least two timber blanks which have been fitted together and glued to each other. A timber element of this kind, and a procedure for manufacturing same, is disclosed in the Finnish Patent No. 79966.
In the reference cited, the timber element is made of a wooden blank which has been sawn from a log so that the heartwood portion of the timber lies closer to the horizontal faces of the ultimate timber element than to its vertical faces exposed to external view. When this principle is followed, cracks will appear in the wooden blank, and also in the timber element, mainly on the sawn surfaces lying close to the heartwood, i.e., in the interior of the timber element.
The drawback embarrassing the procedure of the reference is that the cutting of the wooden blank from the log is done with very special arrangements; the cutting is done, arranging the heartwood portion of the wooden blank to lie closer to two given, opposed sides than to the other two opposed sides. The wooden blanks are joined to each other only by those sides which lie closer to the heartwood portion, to form a timber element. This procedure aims to benefit of the known fact that cracks will form in the wood substance on those surfaces which are closest to the heartwood, when the timber is being dried. However, the procedure implies careful control and it is therefore highly labour-intensive. Moreover, the log is not used efficiently when the wooden blank is cut in this manner. All these circumstances contribute to higher manufacturing costs of the timber element.